Mitsubishi LJ61BT11 User Manual page 334

Description of problem
B1-1
B1-2
B1-3
Unable to link the
entire system.
B1-4
B1-5
B1-6
B2-1
B2-2
A station cannot be
linked occasionally.
B2-3
B2-4
15 - 13
(2) Problems on slave station disconnection (when the CC-Link system
has been normally operated)
Check item
Does any error occur at the
Programmable
programmable controller CPU of
controller CPU check
the master station?
Power supply (for
Is any voltage drop occurring?
communication)
Is there any disconnection, short-
Cables
circuit or faulty connection?
Is there any noise on the
Noise
transmission cable?
Master station failure Is the master station failed?
Is the data link stop instruction
Link stop
being executed properly?
Power supply (for
Is any voltage drop occurring?
communication)
Is there any cable/connector
Cables disconnected or out of
specifications?
Is there any noise on the
Noise
transmission cable?
Slave station failure Is the slave station failed?
Check contents
Check the error code of the
programmable controller CPU.
Check if the module can be
recognized.
Check the power supply of the
master station and all slave
stations.
Check if the cable between the
master station and slave station is
connected properly.
Check if the transmission cable
and power wiring are separated
enough.
Check if the FG is separated from
the power system GND.
Reduce the transmission speed
and then check the occurrence
frequency.
Check if the system operates
properly after replacing the
master station.
Check if the data link stop
(SB0002) is turned on.
Check the power supply at the
faulty station.
Check the connection cable at the
faulty station.
Check the cable of the closest
faulty station from the master
station, when multiple stations are
sequentially faulty to the terminal
of the transmission path.
Check if the transmission cable
and power wiring are separated
enough.
Check if the FG is separated from
the power system GND.
Reduce the transmission speed
and then check the occurrence
frequency.
Replace the failed station and
check the operation.
15 TROUBLESHOOTING
Check procedure
Correct the error code of the
programmable controller CPU.
Refer to MELSEC-L CPU Module
User's Manual (Hardware Design,
Maintenance and Inspection)
Recognize the L series
master/local module properly.
Refer to MELSEC-L CPU Module
User's Manual (Hardware Design,
Maintenance and Inspection)
Set the supplied voltage to within
the specified range.
Connect the cable properly.
Wire the transmission cable and
power wiring as separated as
possible. (recommended to keep
a distance of more than 100mm)
Set FG and the power system
GND apart.
Take measures against noise.
Reduce the transmission speed.
Fix or replace the master station.
Disable the data link stop
(SB0002).
Do not use devices which read
SB0002 simultaneously.
Set the supplied voltage to within
the specified range.
Connect the corresponding cable
properly.
Wire the transmission cable and
power wiring as separated as
possible.
(recommended to keep a
distance of more than 100mm)
Set FG and the power system
GND apart.
Execute the protection against
noise.
Reduce the transmission speed.
Fix or replace the failed slave
station.
Corrective action
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